Commutator dresser



oct. 25, 193s. G. SCHOENFELE', 2,134,151

` COMMUTATOR DREssER OCL 25, 1938. G. scHoENFELD COMMUTATOR DRESSER Filed Feb. 2, 1957 2 Sheets-Sheet 2 Patented Oct. 25, 1938 UNITED vSTATES 'PATEN T OFF ICE COMMUTATOR DRESSER Gustav Schoenfeld, Great Falls, Mont.

Application February 2, 1937, Serial No. 123,703

-6 Claims.

This invention relates tofa device forrdressing the commutator of an electric motor, and one object of the invention is "to provide a device n of this character of such size and construction that it may be easily carried from one place to another `loy a workman and thus A'permit the Workman to redress a commutator withoutltaking thecommutator tofa shop. n y Another object vof the invention is tofsocon- 10 struct the devicetha't, when using it to dress a commutator, it may be appliedto the shaft carrying the commutator kand turned aboutl the shaftv which will be 'held stationary in a vise. It will "thus be seen that use of a lathe is entirely eliminated.

Another object of theinvention is 'to provide improved means for adjustably mounting the blade of the kdresser and also to provide irnproved meansv for shifting the. blade longitudinalpartially in side elevation and showing the 'imv proved commutator dresser applied to the 'shaft of a motor in position' to dress 'the commutator,

Figure '2 Vis a plan Vview looking down upon Figure '1,

Figure 3 isa viewin `end elevation looking'from' the left in `Figure l; t

`Figure 4 is a sectional view taken vertically through the device on the line 4-4 of Figure '1,

and

"Figure 5 is a sectional .viewtaken on the line 5`5 of Figure 1.

Thebody of this commutator dresser is formed from a block of fiber or other material which will be strong and yet of light weight. A shoulder 2projects from one side of the body and through this shoulder extends a shaft 3 formed with a circumferentially extending groove 4 soV that a gpin 5 which is driven into a socket `6 .bored through the shoulder transversely thereof may engage in the groove `and prevent longitudinal shifting of Ithe shaft `3 While permitting free rotary movement `of this shaft. The shaft '3,which may be -referred to as an operating shaft or drive shaftgcarriesa small gear or pinion .l,

and upon referring to Figures 1 and 2 it will heV seen that 'the 'shaft vv@projects AAfrom the forward end of the block and in spaced relation to the pinion 'l carries a pin8 having its ends projecting from opposite sides of the shaft so rthat the extended ends of the ypinmay engage 'in notches or seats 9 formed inthe shank I0 of a crank ll. Therefore, the crank may be detachably applied tothe shaft and the shaft rotated. The pinion .l meshes with a large gear or pinion I2 secured bya set. screw I3 upon a shaft I4 which is of greater length than the shaft 3 and extends through the body I adjacent the opposite side of the body from the shaft 3,' as shown in Figure 4. 'This shaft is also formed withr a circumferentially extending groove I5 to receive a pin I6 driven into a socket I1 formed in the bodyand, therefore, this shaft will also be held against longitudinal movement while permitted to rotate freely. The for-Ward end portion of the shaft I4 projects from the hub of the gear or pinion I2 and carries a pin I8 which extends transversely 4through the shaft with its end portions projecting from opposite sides thereof so that when it is-desired to directly rotate the shaft I4 instead of transmitting rotary motion toit from the shaft 3 the crank may loe detached fromthe shaft 3 and applied to the forwardly projecting end portion of the shaft I4 with ends of the pin I8 engaged in the notches or seats 9. When the crank handle is applied to the shaft v3, rotary motion will be transmitted from the small gear or pinion 'I to the large gear or pinion I2 and the shaft Ill will be slowly turned, whereas, when the crank is applied to the shaft I4, a more rapid rotation of the shaft I4 will be obtained.

The cutter I9 is formed of tool steel and is mounted in a passage or socket 2U formed Vertically through a block 20 of fiber or other suitable material which is of 'light weight but strong. The upper portion of' the -bore or socket 20 `is enlarged to form a circular pocket 2l kin which an internally threaded adjusting sleeve or nut 22 is seated and heldlagainstY longitudinal movement by a pin 23 which is Ydriven Ythrough vthe block from one end thereof and engagesrin a cir-V cumferentially extendinggroove 24 .formed intermediate .the length of the nut or sleeve v22. The portion of the socket 20 belowltherpocket 2| is rectangular in cross section and since the cutter i9 is of similar shape'in vcross sectionthe cutter will be preventedfrom'turning inthe socket. The upper end portion of the cutter is formed with a reduced stem 25 which extends upwardly into the pocket 2l and terminates in a'thread'edhead engaged inthe threadedpore ofthe sleeve or nut. Therefore, when the nut is turned, the cutter will be shifted longitudinally either upwardly or downwardly according to the direction in which the nut is turned and the sharpened lower end of the cutter disposed in proper relation to the commutator to be dressed. Alined openings 21 are formed through the portion of the sleeve or nut which projects upwardly above the block 29 in order that a nail or the like may be passed through these openings and thus permit the nut to be easily turned when the cutter is to be vertically adjusted. A set screw 28 winch is received in a threaded opening 29 formed transversely of the block from one side thereof Y to the bore or socket 29 is provided in orderV that after the cutter has been vertically adjusted the set screw may be tightened and the cutter firmly secured in the adjusted position. It will thus be seen that the cutter cannot accidentally slip out of a set position and cause the commutator to be incorrectly cut during a trimming operation.

Therblock and'the cutter carried thereby must be' shifted longitudinally of the commutator during a dressing operation and in order to slidably mount the block there has been provided a U- shaped yoke 39 formed of steel or other strong metal. This VVyoke is disposed horizontally and its arms v3I extend through openings 32 drilled thrcugh'theupper portion of the bodyY l above the shafts 3an'diI4; Set screws 33 are threaded throughjopenings 34 leading from the upper end of the bodyI andA when tightened firmly grip the arms 3I so that the yoke will be firmly held in place and preventedfrom shifting longitudinally.V Openings 35 which are formed through the block 29at` oppositeV sides of the pocket 2l near the upper end of the block slidably receive the arm 3l anda threaded openingy 36 is'formed through the block above the opening 29'to receive the 'threaded shaft I4. Froman inspection of-Figure'l, it will be readilyunderstood that when the' shaft :I4 is rotated its threaded engagement' with the Nblock 2B will cause the block to Vbe shifted longitudinally upon the armY dressing' operationl is' engaged inV a socket 39V formed in the lower portion of the .body I midway the width thereof.' vThe socket 39 tapersV upwardly, as shown in Figure 3, to a narrow recess 40 and. is lined by Va sheet'm'etal liner 4I which is placedy there toreceivea shaft of smaller diameter and can b'e 'easily withdrawn when a shaft of larger diameter requires it. A thrust bar 42 which is slidably mounted in a throat or seat 43 leading downwardly from the socket 39 is intended to engage under the shaft 38 and in order to vertically adjust the thrust bar there has been providedan adjusting screw 44 carried by a cam 45. 'This cap 45 is formed from the same kind of materialY as the body I and Vis secured thereto by screws 46 which pass through corner portions of the cap and into the lower portion of the body. A collar 41 which is of greater diameter than the width of the throat 43 is formed integral with or fixed to the screwv44 and this collar is seated iny a socket 48 formed in the inner face of the cap about the opening 49 in which the screw loosely fits.V By this arrangement the screw will be held against longitudinal shifting when the cap is secured to the body and since the inner end portion of the screw is threaded into the threaded opening I) formed in the bar 42 rotary motion of the screw will cause the bar to be shifted vertically. Therefore, the bar may be moved into engagement with the shaft 38 and suiiicient binding action applied to the shaft to prevent the shaft from slipping out of the socket 39 while at the same time permitting the body to be turned about the same and the armature should be held stationary by a vise 5I. Other set screws 52 are threaded through the cap to engage the bar 42 near opposite ends thereof and cause the bar to be firmly held in place with its upper face bearing against the shaft 38 for the full length of the shaft.

When this device is in use, the armature must be removed from the motor and secured in a vise. The portion of the motor shaft which projects from the forward end of the commutator 31 is engaged in the socket 39 and the adjusting screws then turned to shift the pressure bar 42 upwardly into engagement with the shaft. In view ofthe shape of the socket and the liner 4I. shafts of different diameters may be received in the socket 39 and when the bar 42 is shifted upwardly the shaft will have a two point contact with the liner or opposite sides of the extension 40 and the bar will engage the shaft at a third point. The shaft will thus be firmly gripped and when the screws 53' are adjusted inwardly to move their inner ends'into engagement .with the pressure bar the body I will be held in engagement with the motor shaft but permitted to turn about the same. The cutter I9 will be out of contact with the commutator 31 duringthis operation. As soon as the body has been applied tothe motor shaft,.the cutter will be shifted towards the commutator by rotating the sleeve or nut 22 until itis very close to the commutator and the crank I I will then be applied to the forwardly projectingV endyof the shaft I4 and turned by a handV grasping the crank handle so that 'the shaft will be turned to adjustthe'block 20 along the yoke until the cutter is at the rear end of the commutator. The body I is held stationary upon the'shaft 38 with thel Vother hand during turning of the shaft I4 by the crank. A final adjustment will then be imparted to theY cutter to move its sharpened end into position to contact with the c'ommutator and theset screw 28 tightened to secure theVA cutter against accidental displacement.l The crankis then removed from the shaft' I4 and applied to the shaft 3 andgrasped so that when the body is`re1eased the crank may be used as a handle Vto turn theentire body about the shaft 38, as indicated by the dotted linesin Figure 3. During swinging movement'of the body about the shaft 38;'the shaft 3 will be turned in the' extension 2 of the body and rotary motion transmitted by the gear orpinion1 to the gear I 2 vwhich is fixed upon the'shaft I4 and the shaft I 4, will beslowly turned.V It will thus be seen that'asthe'body isswung about the motor shaft thecutter will'trim the commutator and turning of the shaft I4 will cause the cutter to be fed longitudinally `of the commutator toward'the forward end'thereof. In view' ofthe ratio between the small gear or pinion 1 and the large` gear I2, the'shaft I4 will be turned very slowly and-in the present instance the shaft'3 must be trim it, the cutter will be disposed between two copper bars of the commutator and the crank handle transferred vto the shaft I4 so that this shaft may be directly turned and the cutter quickly shifted toward the rear end of the commutator. The cutter will then be longitudinally adjusted toward the commutator so that it will cut the commutator as the device is again swung about the motor shaft and swinging movement imparted to the body about the motor shaft until the entire surface of the commutator has been again trimmed. The device can then be removed from the motor shaft and put away until again needed. It will thus be seen that commutators of motors used for electric fans and the like can be very easily and quickly dressed and this accomplished without taking the armature to a shop to have the commutator dressed and the expense of thissaved. It can, therefore, be seen that by use of this device a great saving in both time and money will be realized.

Having thus described the invention, what is claimed as new is:

1. A device of the character described'oomprising a body adapted to be mounted upon a motor shaft for turning movement about the shaft, a track detachably carried by the body and extending laterally from said body in position to be disposed in spaced parallel relation to the motor shaft and an armature carried thereby, a mounting shiftable along said track parallel to the shaft, a cutter carried by said mounting and adjustable radially of the armature whereby its cutting edge may be disposed in position to trim the armature as the body is swung about the motor shaft, and means journaled in said body for swinging the body about the shaft and shifting said mounting along said track to move the cutter along the armature during movement of the body and cutter about the shaft and armature.

2. A device of the character described comprising a body adapted to be mountedupon a motor shaft for turning about the shaft, a yoke extending laterally from said body in position to dispose the yoke in spaced parallel relation to the motor shaft and armature carried thereby, a block slidably carried by said yoke and shiftable longitudinally thereon, a cutter carried by Said block and extending therefrom radially of the armature, means for adjusting the cutter toward and away from the armature to dispose its cutting edge in position to trim the armature as the body is swung about the motor shaft, and means journaled through said body and rotatably supported thereby for swinging the body about the shaft and progressively shifting the block along said yoke and moving the cutter along the armature as the body is swung about the moto-r shaft.

3. A device of the character described comprising a body adapted to be mounted upon a motor shaft for turning movement about the shaft, a U-shaped yoke carried by said body in position to extend rearwardly therefrom in spaced parallel relation to a motor shaft and an armature carried thereby, said yoke having its arms tted into sockets formed in the body, a block slidable along the yoke and having passages through which arms of the yoke extend, a cutter extending through said block and projecting therefrom transversely of the yoke and radially of the armature, means carried by said block for adjusting the cutter longitudinally and shifting its cutting edge towards and away from the armature, and means for shifting said block along said yoke and moving the cutter along the armature as the body is swung about the motor shaft.

4. A device of the character described comprising a body adapted to be mounted upon a motor shaft and swung about the motor shaft, a support carried by said body and extending :rearwardly therefrom in position to dispose the support in spaced parallel relation to a motor shaft and an armature carried thereby, a block slidable along said support, a cutter extending through a passage formed in said block laterally of the armature and having a threaded inner end portion, an adjusting sleeve rotatably mounted in said block and having threaded engagement with the inner end portion of said cutter for adjusting the cutter longitudinally towards and away from the armature when the sleeve is turned, and means for shifting the block along said support and gradually shifting the cutter along an armature as the body is swung about the motor shaft.

5. A device of the character described comprising a body adapted to be mounted upon a motor shaft and turn about the shaft, a lateral support extending rearwardly from said body in spaced parallel relation to a motor shaft and an armature carried thereby, a block slidable along said support, a cutter carried by said block and extending therefrom towards the armature, means for adjusting said cutter radially of the armature, a shaft rotatably carried by said body in spaced parallel relation to the motor shaft and having a threaded portion extending rearwardly from the body and engaged through a threaded opening of said block, and means carried by the body for swinging the body about the motr shaft and transmitting rotary motion to the threaded shaft to adjust the block along said support and move the cutter longitudinally of the armature as the body is swung about the motor shaft.

6. A device of the character described comprising a body adapted to be mounted upon a motor shaft and turn about the shaft, a support extending rearwardly fromV said body in spaced parallel relation to a motor shaft and an armature carried thereby, a block slidable along said support, a cutter carried by said block and eX- tending therefrom towards the armature, means for adjusting said cutter radially of the armature, a shaft rotatably carried by said body and having a threaded portion engaged through a threaded opening of said block, a large gear carried by said threaded shaft, a second shaft rotatably carried by said body, a small gear carried by the second shaft and meshing with the gear of the threaded shaft, and a handle detachably engageable with the second shaft whereby the body may be swung about the motor shaft and rotary motion slowly imparted to the threaded shaft to shift the block along said support and move the cutter along the armature as the body is swung about the motor shaft.

GUSTAV SCHOENFELD. 

